A late Pleistocene long pollen record from Lake Urmia, NW Iran

A palynological study based on two 100-m long cores from Lake Urmia in northwestern Iran provides a vegetation record spanning 200 ka, the longest pollen record for the continental interior of the Near East. During both penultimate and last glaciations, a steppe of Artemisia and Poaceae dominated the upland vegetation with a high proportion of Chenopodiaceae in both upland and lowland saline ecosystems. While Juniperus and deciduous Quercus trees were extremely rare and restricted to some refugia, Hippophaë rhamnoides constituted an important phanerophyte, particularly during the upper last glacial sediments. A pronounced expansion in Ephedra shrub-steppe occurred at the end of the penultimate late-glacial period but was followed by extreme aridity that favoured an Artemisia steppe. Very high lake levels, registered by both pollen and sedimentary markers, occurred during the middle of the last glaciation and upper part of the penultimate glaciation. The late-glacial to early Holocene transition is represented by a succession of Hippophaë, Ephedra, Betula, Pistacia and finally Juniperus and Quercus. The last interglacial period (Eemian), slightly warmer and moister than the Holocene, was followed by two interstadial phases similar in pattern to those recorded in the marine isotope record and southern European pollen sequences

New multi-proxy record shows potential impacts of precipitation on the rise and ebb of Bronze Age and imperial Persian societies in southeastern Iran

The Achaemenids and Sasanian ‘Persian’ Empires were significant political, economic, and social forces in the Late Bronze Age and Late Antiquity Eurasia, respectively, which have left marks on the heritage of the Mediterranean and Middle Eastern world. While attention is often focused on military and political conditions when discussing the prosperity and decline of these imperial powers, their realms, which crossed a variety of environmental settings, were highly dependent on the predictability of rainfall that drove agriculture and effective provisioning. Here, we present a multi-proxy sedimentological, geochemical, and palynological record from a 2.5-m long peat deposit near the excavation site in Konar Sandal near Jiroft in southeastern Iran, covering 4000-850 cal yr BP. Around 3950 cal yr BP a wet period prevailed based on elemental ratios, stable C isotope, pollen, and diagnostic lipids. Between 3900 and 3300 cal yr BP, wet/semi-wet conditions developed with the appearance of Cerealia-type pollen. Dry and windy conditions followed (ca. 3300-2900 cal yr BP), which coincided with the Siberian anticyclones and climatic shifts developing in the Eastern Mediterranean region. Consequently, the Bronze Age settlements around Jiroft, dependent on agriculture, underwent a steady decline. A prolonged wet period followed (ca. 2900-2300 cal yr BP) with the abundance of Sparganium-type pollen and the aquatic lipid proxy (Paq). This change coincided with intensive agricultural practices and the flourishing of the powerful Median and Achaemenid empires. The shift to high Ti/Al ratios coeval with the lowest δ13COM values suggests an increase in aeolian activity and dry conditions ca. 2100-1650 cal yr BP. The Jiroft valley again experienced wet conditions between 1550 and 1300 cal yr BP, which overlapped with the economic prosperity of the middle to late Sasanian empire. The paleoenvironmental reconstruction indicates that wet periods and intensive agriculture coincide with the Persian empires' zenith, political influence, and economic affluence. Therefore, contextualized and detailed paleoenvironmental records are desirable to explore the interplay of political and climatic factors in the development and fragmentation of the ancient settlements and imperial powers in Eurasian history.1. Introduction 2. Geographical setting 3. Materials and methods 3.1. Sampling, magnetic susceptibility, and grain size analysis 3.2. Radiocarbon analyses 3.3. Elemental and mineralogical analyses 3.4. C/N and stable isotope analyses 3.4.1. Lipid extraction 3.5. Pollen analysis 4. Results 4.1. Age-depth model and chronology 4.2. Units 4.2.1. Unit 1 (U 1; 250-189 cm; ca. 4000-3550 cal yr BP) 4.2.2. Unit 2 (U 2; 189-164 cm; ca. 3550-3300 cal yr BP) 4.2.3. Unit 3 (U 3; 164-134 cm; ca. 3300-2900 cal yr BP) 4.2.4. Unit 4 (U 4; 134-106 cm; ca. 2900-2300 cal yr BP) 4.2.5. Unit 5 (U 5; 106-61 cm; ca. 2300-1550 cal yr BP) 4.2.6. Unit 6 (U 6; 61-10 cm; ca. 1550-850 cal yr BP) 5. Discussion 5.1. Paleoclimate preceding the decline of the Jiroft civilization 5.2. The Late Bronze Age decline in Jiroft 5.3. Rise and fall of the Persian Empire 5.3.1. The pre-Islamic period and recent times 6. Conclusion

Late Little Ice Age palaeoenvironmental records from the Anzali and Amirkola Lagoons (south Caspian Sea): Vegetation and sea level changes

This is a postprint version of the article. The official published article can be found from the link below - Copyright @ 2011 Elsevier Ltd.Two internationally important Ramsar lagoons on the south coast of the Caspian Sea (CS) have been studied by palynology on short sediment cores for palaeoenvironmental and palaeoclimatic investigations. The sites lie within a small area of very high precipitation in a region that is otherwise dry. Vegetation surveys and geomorphological investigations have been used to provide a background to a multidisciplinary interpretation of the two sequences covering the last four centuries. In the small lagoon of Amirkola, the dense alder forested wetland has been briefly disturbed by fire, followed by the expansion of rice paddies from AD1720 to 1800. On the contrary, the terrestrial vegetation reflecting the diversity of the Hyrcanian vegetation around the lagoon of Anzali remained fairly complacent over time. The dinocyst and non-pollen palynomorph assemblages, revealing changes that have occurred in water salinity and water levels, indicate a high stand during the late Little Ice Age (LIA), from AD < 1620 to 1800–1830. In Amirkola, the lagoon spit remained intact over time, whereas in Anzali it broke into barrier islands during the late LIA, which merged into a spit during the subsequent sea level drop. A high population density and infrastructure prevented renewed breaking up of the spit when sea level reached its maximum (AD1995). Similar to other sites in the region around the southern CS, these two lagoonal investigations indicate that the LIA had a higher sea level as a result of more rainfall in the drainage basin of the CS.The coring and the sedimentological analyses were funded by the Iranian National Institute for Oceanography in the framework of a research project entitled “Investigation of the Holocene sediment along the Iranian coast of Caspian Sea: central Guilan”. The radiocarbon date of core HCGL02 was funded by V. Andrieu (Europôle Méditerranéen de l'Arbois, France) and that of core HCGA04 by Brunel University

Diagnosis and Management of Antibody‐Mediated Rejection: Current Status and Novel Approaches

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102649/1/ajt12589.pd

COVID-19-associated glomerulopathy and high-risk apol1 genotype; basis for a two-hit mechanism of injury? A narrative review on recent findings

Kidney is one of the most common organs affected by coronavirus disease 2019 (COVID-19) after the respiratory and immune systems. Among the renal parenchymal components, the tubulointerstitial compartment is presumed to be the prime target of injury in COVID-19. The main mechanism of renal tubular damage by COVID-19 is considered to be indirect, i.e., cytokine-mediated injury. A proportion of infected individuals mount a strong inflammatory response to the virus by an exaggerated immune response of the body, namely cytokine storm. Sudden and massive release of cytokines may lead to serious systemic hyper-inflammation and renal tubular injury and inflammation resulting in acute renal failure. In addition, a number of cases of glomerulopathies, particularly collapsing glomerulopathy (CG) have been reported, predominantly in people of African ancestry, as a rare form of kidney involvement by SARS-CoV-2 that may originate from the background genetic susceptibility in this population complicated by the second hit of SARS-CoV-2 infection, either directly or indirectly. It is noteworthy that renal injury in COVID-19 could be severe in individuals of African origin due to the aforementioned genetic susceptibility, especially the presence of high-risk apolipoprotein L1 (APOL1) genotypes. Although the exact mechanism of kidney injury by SARS-CoV-2 is as yet unknown, multiple mechanisms are likely involved in renal damage caused by this virus. This review was aimed to summarize the salient points of pathogenesis of kidney injury, particularly glomerular injury in COVID-19 disease in the light of published data. A clear understanding of these is imperative for the proper management of these cases. For this review, a search was made of Google Scholar, Web of Science, Scopus, EBSCO and PubMed for finding English language articles related to COVID-19, kidney injury and glomerulopathy. From the information given in finally selected papers, the key aspects regarding glomerular involvement in COVID-19 were drawn out and are presented in this descriptive review

20,000 years of societal vulnerability and adaptation to climate change in southwest Asia.

The Fertile Crescent, its hilly flanks and surrounding drylands has been a critical region for studying how climate has influenced societal change, and this review focuses on the region over the last 20,000 years. The complex social, economic, and environmental landscapes in the region today are not new phenomena and understanding their interactions requires a nuanced, multidisciplinary understanding of the past. This review builds on a history of collaboration between the social and natural palaeoscience disciplines. We provide a multidisciplinary, multiscalar perspective on the relevance of past climate, environmental, and archaeological research in assessing present day vulnerabilities and risks for the populations of southwest Asia. We discuss the complexity of palaeoclimatic data interpretation, particularly in relation to hydrology, and provide an overview of key time periods of palaeoclimatic interest. We discuss the critical role that vegetation plays in the human-climate-environment nexus and discuss the implications of the available palaeoclimate and archaeological data, and their interpretation, for palaeonarratives of the region, both climatically and socially. We also provide an overview of how modelling can improve our understanding of past climate impacts and associated change in risk to societies. We conclude by looking to future work, and identify themes of "scale" and "seasonality" as still requiring further focus. We suggest that by appreciating a given locale's place in the regional hydroscape, be it an archaeological site or palaeoenvironmental archive, more robust links to climate can be made where appropriate and interpretations drawn will demand the resolution of factors acting across multiple scales. This article is categorized under:Human Water > Water as Imagined and RepresentedScience of Water > Water and Environmental ChangeWater and Life > Nature of Freshwater Ecosystems

Human impact on the hydroenvironment of Lake Parishan, SW Iran, through the late Holocene

A multiproxy record from Lake Parishan, SW Iran, shows human impact on the lake and its catchment over the last 4000 years. The Parishan record provides evidence of changes in lake hydrology, from ostracod, diatom and isotope analyses, that are directly linked to human activity in the catchment; recorded by pollen and charcoal and supported by regional archaeological and historical data. The lake ostracod fauna is particularly sensitive to human induced catchment alterations and allow us to identify changes in catchment hydrology that are due to more than a simple change in precipitation: evaporation state. Oxygen isotope data from endogenic carbonates follow these faunal changes but also displays a longer trend to more positive values through the period, coincident with regional patterns of water balance for the late Holocene in the eastern Mediterranean

Death with functioning kidney transplant: an obituarial analysis

Death with a functioning kidney graft (DWFG) is now a major cause of graft loss after renal transplantation, occurring in up to 40% of cases. Its occurrence provides insight into the medical care of subjects with a functioning kidney transplant. In this study, we used the time to DWFG as an endpoint, to test whether improved medical care has contributed to better kidney transplant outcomes. We used single-center data from the Milwaukee Regional Medical Center and Froedtert Hospital, on kidney-only transplants from 1969 through 2005. A total of 3,157 kidney transplants were done at our center during this time. There were 714 deaths with functioning kidney. We also recorded the major causes of DWFG over the time period from 1969 through 2005 divided into 3 epochs. The data were analyzed as a serial collection of yearly obituaries. The time to DWFG has increased to 10 years despite a 20-year increase in the mean age of transplant recipients over the same time period. Better pre-transplant evaluation, improved treatments for hypertension and hyperlipidemia, improved management of acute myocardial infarction, superior immunosuppressive protocols and better prophylaxis and treatment of infectious diseases have all likely contributed to this trend

Heat shock proteins in chronic kidney disease

Heat shock proteins (HSP) form a heterogenous, evolutionarily conserved group of molecules with high sequence homology. They mainly act as intracellular chaperones, protecting the protein structure and folding under stress conditions. The extracellular HSP, released in the course of damage or necrosis, play a pivotal role in the innate and adaptive immune responses. They also take part in many pathological processes. The aim of this review is to update the recent developments in the field of HSP in chronic kidney disease (CKD), in regard to three different aspects. The first is the assessment of the role of HSP, either positive or deleterious, in the pathogenesis of CKD and the possibilities to influence its progression. The second is the impact of dialysis, being a potentially modifiable stressor, on HSP and the attempt to assess the value of these proteins as the biocompatibility markers. The last area is that of kidney transplantation and the potential role of HSP in the induction of the immune tolerance in kidney recipients

Ena/VASP proteins have an anti-capping independent function in filopodia formation

Author Posting. © American Society for Cell Biology, 2007. This article is posted here by permission of American Society for Cell Biology for personal use, not for redistribution. The definitive version was published in Molecular Biology of the Cell 18 (2007): 2579-2591, doi:10.1091/mbc.E06-11-0990.Filopodia have been implicated in a number of diverse cellular processes including growth-cone path finding, wound healing, and metastasis. The Ena/VASP family of proteins has emerged as key to filopodia formation but the exact mechanism for how they function has yet to be fully elucidated. Using cell spreading as a model system in combination with small interfering RNA depletion of Capping Protein, we determined that Ena/VASP proteins have a role beyond anticapping activity in filopodia formation. Analysis of mutant Ena/VASP proteins demonstrated that the entire EVH2 domain was the minimal domain required for filopodia formation. Fluorescent recovery after photobleaching data indicate that Ena/VASP proteins rapidly exchange at the leading edge of lamellipodia, whereas virtually no exchange occurred at filopodial tips. Mutation of the G-actin–binding motif (GAB) partially compromised stabilization of Ena/VASP at filopodia tips. These observations led us to propose a model where the EVH2 domain of Ena/VASP induces and maintains clustering of the barbed ends of actin filaments, which putatively corresponds to a transition from lamellipodial to filopodial localization. Furthermore, the EVH1 domain, together with the GAB motif in the EVH2 domain, helps to maintain Ena/VASP at the growing barbed ends.This work was supported in part by National Institutes of Health Grants GM7542201 to D.A.A., GM58801 to F.B.G., and GM62431 to G.G.B. and by Cell Migration Consortium Grants GM64346 to D.A.A and G.G.B